Collapsible tap.



J. P. LAVIGNE. COLLAPSIBLE TAP. APPLICATION FILED NOV. 22. 1913.

LWQML. PatentedJuly 11, 1916.

2 SHEETS-SHEET l- J. P. LAVIGNE.

COLLAPSIBLE TAP. APPLICATION FILED NOV. 22. IBIS.

1 ,1 9,56 1|. Patented July 11, 1916.

2 SHEETS-SHEET 2.

I I I lllllllllllllll g6 w 0 53%" A' JOSEPH P. LAVIGN'E, OF DETROIT, MICHIGAN.

COLLAPSIBLE TAP.

Application filed November 22, 1913.

To all whom it may concern:

Be it known that I, Josnri-r P. LAVIGNE, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in C01- lapsible Taps, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a collapsible tap for use on lathes, screw-machines, boring machines and the like whereby the dies are rigidly held to their work and whereby accurate adjustment is obtainable.

The invention also includes means that permit the work of the tool in a compara- I tively small opening and an adjustment or interchange of dies through a wide range.

The invention consists in the matters hereinafter set forth and more particularly pointed out in the appended claims.

In the drawings, Figure 1 is a view, partially in elevation and partially in section, of a tap that embodies features of the invention; Fig. 2 is an end view thereof; Fig. 3 is a view taken in section on or about line TIL-TIT of Fig. 1; Fig. 4: is a view in section taken on or about line IVTV of Fig. 1; Fig. 5 is a view that is partially in elevation and partially on the line of section V-V of Fig. 2; and Fig. 6 is a View in transverse section taken on or about line VI-VT of Fig. 1.

As herein shown, a main head1 has a shank 2 whereby it may be inserted in the tool carrying member of a screw-machine or the like. An outer casing 3 is detachably secured as by screws 4 to a flange of the head 1 and is appropriately apertured to receive the cylindrical shanks 5 oftap dies arranged symmetrically around the axis of rotation of the casing.

The cutting edges of the dies are so disposed in eccentric relation to the axes of the shanks that rotation of the dies throws them from or toward the axis of rotation of the head and the casingvso as to make them operative or inoperative. This simultaneous rotation of the taps on their respective axes is obtained through segmental gear teeth 6 on each meshing with an internal annular gear 7 that maybe turned in. respect to the Specification of Letters Patent.

Patented July 11, 1916.

Serial No. 802,354.

casing 3 by a suitable handle 8. The latter is held by suitable means 9 in frictional engagement with a cover strip- 10 of the casing.

The movement of the gear 7 by means of the handle 8 is opposed by a suitable spring 11 whose ends are respectively anchored to the head 1 and the gear 7 so as to operate both as a torsion and compression spring. The spring holds the gear 7 interlocked with the ratchets 12 of a stop collar 13 when the dies are in cutting position. By means of a worm 14 the collar 13 may. be shifted to adjust the point of engagement so that the taps may be spread open to cut a thread of the required diameter. A check nut 16 and thrust screw 17 are used to effectively hold the worm 14 in position although other adjusting means may be employed if desired. The inner portion of the cylindrical stems 5 of the dies are screw-threaded to engage a bushing 24 that may be rotated in the head by means of a worm spindle 18 or the like mounted similarly to the worm 14 and engaged by suitable teeth on the bushing. Rotation of the bushing 24 thus operates to simultaneously shift the dieslongitudinally in or out as required.

A knock-off headQO is in reciprocable engagement with a nipple 21 forming an outer portion of the casing. Thrust studs 23 connect the head 20 with the gear 7. When the knock-01f head 20 encounters any gage or part of the work to which the tap is applied so that it is moved backward, the gear moves out of engagement with the ratchets 12 and is snapped back to initial position by the action of the spring so as to turn the dies out of operative position or into collapsed position. As a result of this construction the tap is available for use in narrow or restricted places as the knockoff and other operating mechanism are within the outer limits ofthe tools. It is positive in its action and the tap members or the dies proper are supported for substantially their entire length to within a very short dis tance of their cutting edges. This insures rigidity and freedom from vibration.

Obviously, changes in the details of construction may be made without departing fronlthe spirit of my inventi n and. I do not care to limit myself to any particular form or arrangement of parts within the scope of the appended claims.

What I claim is j 1. A collapsible tap comprising a main head, an outer casing mounted thereon, cutting dies journaled in the head and casing in symmetrical relation and around the axis of rotation, a member rotatable in the head in engagement with the several dies for projecting them simultaneously from the head, a spindle in the head adapted to operate the die projecting means, a rotatable member in the casing adapted to simultaneously engage and turn the dies, a knock-01f member on the casing engaging the die rotating member and adapted to reciprocate the latter longitudinally of the casing and a spring 'member in the casing adapted to yieldingly project the dies and turning member against the thrust of the knock-off member and normally retain the die rotating members in initial position.

2. A collapsible tap comprising a main head, a casing thereon, cutting'dies journaled in the head and casing in symmetrical relation to the axis of rotation, a bushing rotatable in the head in screwthreaded engagement with the several dies for projecting them simultaneously from the head, a

' worm spindle in the head adapted to turn the bushing, an annular gear journaled in the casing segmental teeth on the dies meshing with the annular gear, a handle for shifting the gear to turn the dies into operative position, a stop collar in the head adapted to interlock with the gear when the dies are in cutting position, a spring member in compression and tension between the head and annular gear adapted to normally I hold the latter interlocked with the stop collar and to turn the latter when released from the stop collar to inoperative position, and a knock-01f member adapted to shift the gear out of engagement with the stop collar.

3 A collapsible tap comprising a rotatable head, a casing on the head, cutting dies having cylindrical shanks journaled in the head and casing in symmetrical relation with the axes of rotation and with cutting edges on the projecting portions eccentric to worm'teeth on the bushing, a manually op- 30 tabl e in the casingand head adapted tofin terloek with the annular gear when the latthe shank axes, segmental gear teeth on the shank axes, a bushing rotatablein the head in screwthreaded engagement with the shank for projecting the latter from the head,

erable worm spindle in the; head meshing with the'bushing teeth, an annular gear j ournaled in the head and casing in mesh with the teeth ofthe shanks, a stop collar rota ter has turned the dies into cutting position,

manually operable worm spindle in thehead and'casing 'in' mesh with the teeth of the stop collar, a spring member in the casing secured to the head and adapted to hold the gear in engagement with the stop collar and to turn the gear when released from the stop collar to inoperative position, and a knock-off member reciprocable on the casing adapted to shift the gear out of engagement with the collar.

4. A collapsible tap comprising a rotatable head, a casing on the head, cutting dies hav ing cylindrical shanks journaled in the head and casing in symmetrical relation with the axis of rotation and with cutting edges on the projecting portions eccentric to the shank axes, segmental gear teeth on the shank axes, a bushing rotatable in the head in screwthreaded engagement with the shanks for projecting the latter from the head, worm teeth on the bushing, a manually operable worm spindle in the head meshing with the bushing teeth, an annular gear ournaled in the head and casing in mesh with the teeth of the shanks, a stop collar rotatable in the casing and head adapted to interlock with the annular gear when the latter has turned the dies into cutting position, a manually operable worm spindle in the head and casing in mesh with the teeth of the stop collar, a spring member in the casing secured to the head and adapted to hold the gear in engagement with the stop collar and to turn the gear when released from the stop collar to inoperative position, a knock-oif member reciprocable on the easing adapted to shift the gear out of engagement with the collar, and a manually operable member extending from the gear in frictional engagement with the casing for turning the gear into position to interlock with the stop collar.

5. A collapsible tap comprising a rotatable head, dies having cylindrical shanks journaled in the head in symmetrical relation to the axis of rotation thereof, cutting edges inthe dies in eccentric relation to the shank axes, gear teeth on each of the shanks, a bushing rotatable in the head in screwthreaded engagement with each of the shanks, worm teeth on the bushing, a manually operable worm spindle in mesh with the worm teeth, a stop collar rotatable in the casing, a worm spindle engaging the stop collar for turning the latter, an annular gear journaled in the casing in mesh with the shank teeth and adapted to bear outwardly against the stop collar, a spiral spring encirclingthe die shanks in compression between the head and the gear and projecting the latter against the stop collar, the end 1001'- tions of the spring being locked respectively with the head and the gear for throwing the latter with the dies to inoperative position when disengaged from the stop collar, a knock-off member reciprocable on the casing secured to the gear and adapted to shift the latter against the action of the spring In testimony whereof I afiix my signature out of engagement With the collar and a in presence of tWo Witnesses. manually operable member extending from the gear through the casing With Which it is JOSEPH LAVIGNE' in frictional engagement for moving the Witnesses:

gear into interlocked engagement With the O. R. STIOKNEY,

stop collar. ()TTO H. FRANKEL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of latents, Washington, D. G. 

